Parking Sensor & DHT22 combinated

[ghislain]

Hi all,

I'm trying to do a sketch with both combinated parking sensor and dht22 but i'm failed.
Each sketch is working separetely but when i 'm trying together, dht22 values are bad.

This is my sketch :

/**
* The MySensors Arduino library handles the wireless radio link and protocol
* between your home built sensors/actuators and HA controller of choice.
* The sensors forms a self healing radio network with optional repeaters. Each
* repeater and gateway builds a routing tables in EEPROM which keeps track of the
* network topology allowing messages to be routed to nodes.
*
* Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
* Copyright (C) 2013-2015 Sensnology AB
* Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
*
* Documentation: http://www.mysensors.org
* Support Forum: http://forum.mysensors.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
*******************************
*
* REVISION HISTORY
* Version 1.0 - Created by Henrik Ekblad
* 
* DESCRIPTION
* Parking sensor using a neopixel led ring and distance sensor (HC-SR04).
* Configure the digital pins used for distance sensor and neopixels below.
* NOTE! Remeber to feed leds and distance sensor serparatly from your Arduino. 
* It will probably not survive feeding more than a couple of LEDs. You 
* can also adjust intesity below to reduce the power requirements.
* 
* Sends parking status to the controller as a DOOR sensor if SEND_STATUS_TO_CONTROLLER 
* is defined below. You can also use this _standalone_ without any radio by 
* removing the SEND_STATUS_TO_CONTROLLER define.
*/

#define SEND_STATUS_TO_CONTROLLER  // Put a comment on this line for standalone mode

#include <Adafruit_NeoPixel.h>
#include <NewPing.h>

#ifdef SEND_STATUS_TO_CONTROLLER
// Enable debug prints to serial monitor
//#define MY_DEBUG 

// Enable and select radio type attached Disabled
#define MY_RADIO_NRF24
#define MY_RF24_PA_LEVEL RF24_PA_LOW

// Noeud de l'objet / Object Node
#define MY_NODE_ID 1

#include <SPI.h>
#include <MySensors.h>
#include <DHT.h> 
#endif

#define DHTPIN 3
#define DHTTYPE DHT22
#define NEO_PIN      8 // NeoPixels input pin
#define TRIGGER_PIN  6  // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN     5  // Arduino pin tied to echo pin on the ultrasonic sensor.

#define NUMPIXELS      24 // Number of nexpixels in ring/strip
#define MAX_INTESITY   5 // Intesity of leds (in percentage). Remember more intesity requires more power.

// The maximum rated measuring range for the HC-SR04 is about 400-500cm.
#define MAX_DISTANCE 150 // Max distance we want to start indicating green (in cm)
#define PANIC_DISTANCE 15 // Mix distance we red warning indication should be active (in cm)
#define PARKED_DISTANCE 100 // Distance when "parked signal" should be sent to controller (in cm)

#define PARK_OFF_TIMEOUT 30000 // Number of milliseconds until turning off light when parked.

// Note that for older NeoPixel strips you might need to change the third parameter--see the strandtest
// example for more information on possible values.

Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, NEO_PIN, NEO_GRB + NEO_KHZ800);

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance.

#ifdef SEND_STATUS_TO_CONTROLLER
#define CHILD_ID_TEMP 0  
#define CHILD_ID_HUM 1
#define CHILD_ID 2

MyMessage msgHum(CHILD_ID_HUM, V_HUM);
MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);
MyMessage msg(CHILD_ID,V_TRIPPED);

float lastTemp;
float lastHum;
boolean metric = true; 

#endif
unsigned long sendInterval = 90000;  // Send park status at maximum every 5 second.
unsigned long lastSend;

int oldParkedStatus=-1;

unsigned long blinkInterval = 100; // blink interval (milliseconds)
unsigned long lastBlinkPeriod;
bool blinkColor = true;

// To make a fading motion on the led ring/tape we only move one pixel/distDebounce time
unsigned long distDebounce = 30; 
unsigned long lastDebouncePeriod;
int numLightPixels=0;
int skipZero=0;

void setup() {
 Serial.begin(115200);
 Serial.println("Starting distance sensor");
 pixels.begin(); // This initializes the NeoPixel library.
 Serial.println("Neopixels initialized");
}

#ifdef SEND_STATUS_TO_CONTROLLER
void presentation()  {
 sendSketchInfo("Parking & Temperature & Humidity Sensor", "1.0");
 present(CHILD_ID_TEMP, S_TEMP);
 present(CHILD_ID_HUM, S_HUM);
 present(CHILD_ID, S_DOOR, "Parking Status");
 }
#endif

void loop() {
 unsigned long now = millis();
 unsigned int fullDist = (sonar.ping_median() / US_ROUNDTRIP_CM);
  //Serial.println(fullDist);
 int displayDist = min(fullDist, MAX_DISTANCE);
 if (displayDist == 0 && skipZero<10) {
   // Try to filter zero readings
   skipZero++;
 return;
 }
 // Check if it is time to alter the leds
 if (now-lastDebouncePeriod > distDebounce) {
   lastDebouncePeriod = now;

   // Update parked status
   int parked = displayDist != 0 && displayDist<PARKED_DISTANCE;
   if (parked != oldParkedStatus && now-lastSend > sendInterval) {
     if (parked)
       Serial.println("Car Parked");
     else
       Serial.println("Car Gone");
#ifdef SEND_STATUS_TO_CONTROLLER
     send(msg.set(parked)); 
#endif
     oldParkedStatus = parked;
     lastSend = now;
   }

   if (parked && now-lastSend > PARK_OFF_TIMEOUT) {
     // We've been parked for a while now. Turn off all pixels
     for(int i=0;i<NUMPIXELS;i++){
       pixels.setPixelColor(i, pixels.Color(0,0,0)); 
     }
   } else {
     if (displayDist == 0) {
       // No reading from sensor, assume no object found
       numLightPixels--;
     } else {
       skipZero = 0;
       int newLightPixels = NUMPIXELS - (NUMPIXELS*(displayDist-PANIC_DISTANCE)/(MAX_DISTANCE-PANIC_DISTANCE));
       if (newLightPixels>numLightPixels) {
         // Fast raise
         numLightPixels += max((newLightPixels - numLightPixels) / 2, 1);
       } else if (newLightPixels<numLightPixels) {
         // Slow decent
         numLightPixels--;
       }
     }
 
     if (numLightPixels>=NUMPIXELS) {
       // Do some intense red blinking 
       if (now-lastBlinkPeriod > blinkInterval) {
         blinkColor = !blinkColor;
         lastBlinkPeriod = now;
       }
       for(int i=0;i<numLightPixels;i++){
         pixels.setPixelColor(i, pixels.Color(blinkColor?255*MAX_INTESITY/100:0,0,0)); 
       }              
     } else {
       for(int i=0;i<numLightPixels;i++){
         int r = 255 * i/NUMPIXELS;
         int g = 255 - r;     
         // pixels.Color takes RGB values, from 0,0,0 up to 255,255,255
         pixels.setPixelColor(i, pixels.Color(r*MAX_INTESITY/100,g*MAX_INTESITY/100,0)); 
       }
       // Turn off the rest
       for(int i=numLightPixels;i<NUMPIXELS;i++){
         pixels.setPixelColor(i, pixels.Color(0,0,0)); 
       }
     }
   }
   pixels.show(); // This sends the updated pixel color to the hardware.
 }
DHT dht(DHTPIN, DHTTYPE,3); // Creation d'un objet dht dans la loop sinon les valeurs ne sont pas mesurées au réveil
 float temperature = dht.readTemperature();
 float humidity = dht.readHumidity();
 if (isnan(temperature)) {
     Serial.println("Impossible de lire la temperature sur le DHT");
 } else {
   if (temperature != lastTemp) {
     lastTemp = temperature;
     if (!metric) {
       temperature = dht.readTemperature(true);
     }
     
     Serial.print("T: ");
     Serial.print(temperature);
     Serial.print(" | H: ");
     Serial.println(humidity);
     send(msgTemp.set(temperature, 1));
     send(msgHum.set(humidity, 1));
   } else {
     Serial.println("Temperature identique => on force l'envoi");  
     Serial.print("T: ");
     Serial.print(temperature);
     Serial.print(" | H: ");
     Serial.println(humidity);
     send(msgTemp.set(temperature, 1));
     send(msgHum.set(humidity, 1));
   }
 }  
     }

Somebody could help me ?

Thank you some much guys

[sja]

@ghislain
The example sketch on this site has some code for the dht in setup() https://www.mysensors.org/build/humidity

Maybe you 've forgotten to copy this in your dht script?

[hek]

Seems strange to initialise the DHT all the time in your loop function. You also seem to spam your gateway with humidity-messages. Check your if-statements.

[ghislain]

Hi, i'm very bad in code. So i tryied to assemble 2 sketches.

Gateway is spammed yes...

I think i need to store value of temperature and humidity, store value of parking sensor (car gone or car parked) and send everything together. It would be more clean. But i have no idea to do that.

I'm not familiar neither with void loop / setup....

Thanks

[ghislain]

This is much better, but too much temperature and humidity value sended

/**
  *******************************
 *
 * REVISION HISTORY
 * Version 1.0 - Compilation of DhtTemperature & Parking Sensor
 * 
 * DESCRIPTION
 * Parking sensor using a neopixel led ring and distance sensor (HC-SR04).
 * Configure the digital pins used for distance sensor and neopixels below.
 * NOTE! Remeber to feed leds and distance sensor serparatly from your Arduino. 
 * It will probably not survive feeding more than a couple of LEDs. You 
 * can also adjust intesity below to reduce the power requirements.
 * 
 * Sends parking status to the controller as a DOOR sensor if SEND_STATUS_TO_CONTROLLER 
 * is defined below. You can also use this _standalone_ without any radio by 
 * removing the SEND_STATUS_TO_CONTROLLER define.
 */

#define SEND_STATUS_TO_CONTROLLER  // Put a comment on this line for standalone mode

// Enable debug prints to serial monitor
#define MY_DEBUG 

// Enable and select radio type attached Disabled
#define MY_RADIO_NRF24
#define MY_RF24_PA_LEVEL RF24_PA_LOW

// Noeud de l'objet / Object Node
#define MY_NODE_ID 1

#include <Adafruit_NeoPixel.h>
#include <NewPing.h>
#include <SPI.h>
#include <MySensors.h>
#include <DHT.h> 

// Set this to the pin you connected the DHT's data pin to
#define DHT_DATA_PIN 3

#define NEO_PIN      8 // NeoPixels input pin
#define TRIGGER_PIN  6  // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN     5  // Arduino pin tied to echo pin on the ultrasonic sensor.

#define NUMPIXELS      24 // Number of nexpixels in ring/strip
#define MAX_INTESITY   5 // Intesity of leds (in percentage). Remember more intesity requires more power.

// The maximum rated measuring range for the HC-SR04 is about 400-500cm.
#define MAX_DISTANCE 150 // Max distance we want to start indicating green (in cm)
#define PANIC_DISTANCE 15 // Mix distance we red warning indication should be active (in cm)
#define PARKED_DISTANCE 100 // Distance when "parked signal" should be sent to controller (in cm)

#define PARK_OFF_TIMEOUT 30000 // Number of milliseconds until turning off light when parked.

// Note that for older NeoPixel strips you might need to change the third parameter--see the strandtest
// example for more information on possible values.

Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, NEO_PIN, NEO_GRB + NEO_KHZ800);

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance.

// Set this offset if the sensor has a permanent small offset to the real temperatures
#define SENSOR_TEMP_OFFSET 0

// Sleep time between sensor updates (in milliseconds)
// Must be >1000ms for DHT22 and >2000ms for DHT11
static const uint64_t UPDATE_INTERVAL = 5000;

// Force sending an update of the temperature after n sensor reads, so a controller showing the
// timestamp of the last update doesn't show something like 3 hours in the unlikely case, that
// the value didn't change since;
// i.e. the sensor would force sending an update every UPDATE_INTERVAL*FORCE_UPDATE_N_READS [ms]
static const uint8_t FORCE_UPDATE_N_READS = 10;

#define CHILD_ID_HUM 0  
#define CHILD_ID_TEMP 1
#define CHILD_ID 2

float lastTemp;
float lastHum;
uint8_t nNoUpdatesTemp;
uint8_t nNoUpdatesHum;
boolean metric = true; 

MyMessage msgHum(CHILD_ID_HUM, V_HUM);
MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);
MyMessage msg(CHILD_ID,V_TRIPPED);
DHT dht;

unsigned long sendInterval = 5000;  // Send park status at maximum every 5 second.
unsigned long lastSend;

int oldParkedStatus=-1;

unsigned long blinkInterval = 100; // blink interval (milliseconds)
unsigned long lastBlinkPeriod;
bool blinkColor = true;

// To make a fading motion on the led ring/tape we only move one pixel/distDebounce time
unsigned long distDebounce = 30; 
unsigned long lastDebouncePeriod;
int numLightPixels=0;
int skipZero=0;


void presentation()  {
  sendSketchInfo("ParkingTemperatureAndHumiditySensor", "1.0");
  present(CHILD_ID_TEMP, S_TEMP);
  present(CHILD_ID_HUM, S_HUM);
  present(CHILD_ID, S_DOOR, "Parking Status");

   metric = getControllerConfig().isMetric;
  }

void setup() 
{
  dht.setup(DHT_DATA_PIN); // set data pin of DHT sensor
  if (UPDATE_INTERVAL <= dht.getMinimumSamplingPeriod()) {
    Serial.println("Warning: UPDATE_INTERVAL is smaller than supported by the sensor!");
  }
  // Sleep for the time of the minimum sampling period to give the sensor time to power up
  // (otherwise, timeout errors might occure for the first reading)
  sleep(dht.getMinimumSamplingPeriod());
  
  Serial.println("Starting distance sensor");
  pixels.begin(); // This initializes the NeoPixel library.
  Serial.println("Neopixels initialized");
  }


void loop() 
{
    // Force reading sensor, so it works also after sleep()
  dht.readSensor(true);
  
  // Get temperature from DHT library
  float temperature = dht.getTemperature();
  if (isnan(temperature)) {
    Serial.println("Failed reading temperature from DHT!");
  } else if (temperature != lastTemp || nNoUpdatesTemp == FORCE_UPDATE_N_READS) {
    // Only send temperature if it changed since the last measurement or if we didn't send an update for n times
    lastTemp = temperature;
    if (!metric) {
      temperature = dht.toFahrenheit(temperature);
    }
    // Reset no updates counter
    nNoUpdatesTemp = 0;
    temperature += SENSOR_TEMP_OFFSET;
    send(msgTemp.set(temperature, 1));

    #ifdef MY_DEBUG
    Serial.print("T: ");
    Serial.println(temperature);
    #endif
  } else {
    // Increase no update counter if the temperature stayed the same
    nNoUpdatesTemp++;
  }

  // Get humidity from DHT library
  float humidity = dht.getHumidity();
  if (isnan(humidity)) {
    Serial.println("Failed reading humidity from DHT");
  } else if (humidity != lastHum || nNoUpdatesHum == FORCE_UPDATE_N_READS) {
    // Only send humidity if it changed since the last measurement or if we didn't send an update for n times
    lastHum = humidity;
    // Reset no updates counter
    nNoUpdatesHum = 0;
    send(msgHum.set(humidity, 1));
    
    #ifdef MY_DEBUG
    Serial.print("H: ");
    Serial.println(humidity);
    #endif
  } else {
    // Increase no update counter if the humidity stayed the same
    nNoUpdatesHum++;
  }

  // Sleep for a while to save energy
 // sleep(UPDATE_INTERVAL); 


  unsigned long now = millis();
  unsigned int fullDist = (sonar.ping_median() / US_ROUNDTRIP_CM);
  
  int displayDist = min(fullDist, MAX_DISTANCE);
  if (displayDist == 0 && skipZero<10) {
    // Try to filter zero readings
    skipZero++;
  return;
  }
  // Check if it is time to alter the leds
  if (now-lastDebouncePeriod > distDebounce) {
    lastDebouncePeriod = now;

    // Update parked status
    int parked = displayDist != 0 && displayDist<PARKED_DISTANCE;
    if (parked != oldParkedStatus && now-lastSend > sendInterval) {
      if (parked)
        Serial.println("Car Parked");
      else
        Serial.println("Car Gone");
#ifdef SEND_STATUS_TO_CONTROLLER
      send(msg.set(parked)); 
#endif
      oldParkedStatus = parked;
      lastSend = now;
    }

    if (parked && now-lastSend > PARK_OFF_TIMEOUT) {
      // We've been parked for a while now. Turn off all pixels
      for(int i=0;i<NUMPIXELS;i++){
        pixels.setPixelColor(i, pixels.Color(0,0,0)); 
      }
    } else {
      if (displayDist == 0) {
        // No reading from sensor, assume no object found
        numLightPixels--;
      } else {
        skipZero = 0;
        int newLightPixels = NUMPIXELS - (NUMPIXELS*(displayDist-PANIC_DISTANCE)/(MAX_DISTANCE-PANIC_DISTANCE));
        if (newLightPixels>numLightPixels) {
          // Fast raise
          numLightPixels += max((newLightPixels - numLightPixels) / 2, 1);
        } else if (newLightPixels<numLightPixels) {
          // Slow decent
          numLightPixels--;
        }
      }
  
      if (numLightPixels>=NUMPIXELS) {
        // Do some intense red blinking 
        if (now-lastBlinkPeriod > blinkInterval) {
          blinkColor = !blinkColor;
          lastBlinkPeriod = now;
        }
        for(int i=0;i<numLightPixels;i++){
          pixels.setPixelColor(i, pixels.Color(blinkColor?255*MAX_INTESITY/100:0,0,0)); 
        }              
      } else {
        for(int i=0;i<numLightPixels;i++){
          int r = 255 * i/NUMPIXELS;
          int g = 255 - r;     
          // pixels.Color takes RGB values, from 0,0,0 up to 255,255,255
          pixels.setPixelColor(i, pixels.Color(r*MAX_INTESITY/100,g*MAX_INTESITY/100,0)); 
        }
        // Turn off the rest
        for(int i=numLightPixels;i<NUMPIXELS;i++){
          pixels.setPixelColor(i, pixels.Color(0,0,0)); 
        }
      }
    }
    pixels.show(); // This sends the updated pixel color to the hardware.
  }

      }

How can i get out value of temp and hum out of the loop ?

I can't put delay because the led ring need to be refreshed very fastly.

[gohan]

There is a minimum time before you can read values from dht, so you could set a check to read dht every 30000 millis so this way you can have the blinking leds and some delay between temp readings

[ghislain]

Yes, thanks guys.

/**
  *******************************
 *
 * REVISION HISTORY
 * Version 1.0 - Compilation of DhtTemperature & Parking Sensor
 * 
 * DESCRIPTION
 * Parking sensor using a neopixel led ring and distance sensor (HC-SR04).
 * Configure the digital pins used for distance sensor and neopixels below.
 * NOTE! Remeber to feed leds and distance sensor serparatly from your Arduino. 
 * It will probably not survive feeding more than a couple of LEDs. You 
 * can also adjust intesity below to reduce the power requirements.
 * 
 * Sends parking status to the controller as a DOOR sensor if SEND_STATUS_TO_CONTROLLER 
 * is defined below. You can also use this _standalone_ without any radio by 
 * removing the SEND_STATUS_TO_CONTROLLER define.
 */

#define SEND_STATUS_TO_CONTROLLER  // Put a comment on this line for standalone mode

// Enable debug prints to serial monitor
#define MY_DEBUG 

// Enable and select radio type attached Disabled
#define MY_RADIO_NRF24
#define MY_RF24_PA_LEVEL RF24_PA_LOW

// Noeud de l'objet / Object Node
#define MY_NODE_ID 1

#include <Adafruit_NeoPixel.h>
#include <NewPing.h>
#include <SPI.h>
#include <MySensors.h>
#include <DHT.h> 

// Set this to the pin you connected the DHT's data pin to
#define DHT_DATA_PIN 3

#define NEO_PIN      8 // NeoPixels input pin
#define TRIGGER_PIN  6  // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN     5  // Arduino pin tied to echo pin on the ultrasonic sensor.

#define NUMPIXELS      24 // Number of nexpixels in ring/strip
#define MAX_INTESITY   5 // Intesity of leds (in percentage). Remember more intesity requires more power.

// The maximum rated measuring range for the HC-SR04 is about 400-500cm.
#define MAX_DISTANCE 150 // Max distance we want to start indicating green (in cm)
#define PANIC_DISTANCE 15 // Mix distance we red warning indication should be active (in cm)
#define PARKED_DISTANCE 100 // Distance when "parked signal" should be sent to controller (in cm)

#define PARK_OFF_TIMEOUT 30000 // Number of milliseconds until turning off light when parked.

// Note that for older NeoPixel strips you might need to change the third parameter--see the strandtest
// example for more information on possible values.

Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, NEO_PIN, NEO_GRB + NEO_KHZ800);

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance.

// Set this offset if the sensor has a permanent small offset to the real temperatures
#define SENSOR_TEMP_OFFSET 0

// Sleep time between sensor updates (in milliseconds)
// Must be >1000ms for DHT22 and >2000ms for DHT11
static const uint64_t UPDATE_INTERVAL = 90000;

// Force sending an update of the temperature after n sensor reads, so a controller showing the
// timestamp of the last update doesn't show something like 3 hours in the unlikely case, that
// the value didn't change since;
// i.e. the sensor would force sending an update every UPDATE_INTERVAL*FORCE_UPDATE_N_READS [ms]
static const uint16_t FORCE_UPDATE_N_READS = 60000;

#define CHILD_ID_HUM 0  
#define CHILD_ID_TEMP 1
#define CHILD_ID 2

float lastTemp;
char lastHum;
uint8_t nNoUpdatesTemp;
uint8_t nNoUpdatesHum;
boolean metric = true; 

MyMessage msgHum(CHILD_ID_HUM, V_HUM);
MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);
MyMessage msg(CHILD_ID,V_TRIPPED);
DHT dht;

unsigned long sendInterval = 5000;  // Send park status at maximum every 5 second.
unsigned long lastSend;

int oldParkedStatus=-1;

unsigned long blinkInterval = 100; // blink interval (milliseconds)
unsigned long lastBlinkPeriod;
bool blinkColor = true;

// To make a fading motion on the led ring/tape we only move one pixel/distDebounce time
unsigned long distDebounce = 30; 
unsigned long lastDebouncePeriod;
int numLightPixels=0;
int skipZero=0;


void presentation()  {
  sendSketchInfo("ParkingTemperatureAndHumiditySensor", "1.0");
  present(CHILD_ID_TEMP, S_TEMP);
  present(CHILD_ID_HUM, S_HUM);
  present(CHILD_ID, S_DOOR, "Parking Status");

   metric = getControllerConfig().isMetric;
  }

void setup() 
{
  dht.setup(DHT_DATA_PIN); // set data pin of DHT sensor
  if (UPDATE_INTERVAL <= dht.getMinimumSamplingPeriod()) {
    Serial.println("Warning: UPDATE_INTERVAL is smaller than supported by the sensor!");
  }
  // Sleep for the time of the minimum sampling period to give the sensor time to power up
  // (otherwise, timeout errors might occure for the first reading)
  sleep(dht.getMinimumSamplingPeriod());
  
  Serial.println("Starting distance sensor");
  pixels.begin(); // This initializes the NeoPixel library.
  Serial.println("Neopixels initialized");
  }


void loop() 
{
  // Get temperature from DHT library
  float temperature = dht.getTemperature();
  if (isnan(temperature)) {
    Serial.println("Failed reading temperature from DHT!");
  } else if (temperature != lastTemp || nNoUpdatesTemp == FORCE_UPDATE_N_READS) {
    // Only send temperature if it changed since the last measurement or if we didn't send an update for n times
    lastTemp = temperature;
       if (!metric) {
      temperature = dht.toFahrenheit(temperature);
    }
    // Reset no updates counter
    nNoUpdatesTemp = 0;
    temperature += SENSOR_TEMP_OFFSET;
    send(msgTemp.set(temperature, 1));

      } 
      else {
    // Increase no update counter if the temperature stayed the same
    nNoUpdatesTemp++;
  }

  // Get humidity from DHT library
  char humidity = dht.getHumidity();
  if (isnan(humidity)) {
    Serial.println("Failed reading humidity from DHT");
  } else if (humidity != lastHum || nNoUpdatesHum == FORCE_UPDATE_N_READS) {
    // Only send humidity if it changed since the last measurement or if we didn't send an update for n times
    lastHum = humidity;
    // Reset no updates counter
    nNoUpdatesHum = 0;
    send(msgHum.set(humidity, 0));
    
      } 
      else {
    // Increase no update counter if the humidity stayed the same
    nNoUpdatesHum++;
  }

  
  unsigned long now = millis();
  unsigned int fullDist = (sonar.ping_median() / US_ROUNDTRIP_CM);
  
  int displayDist = min(fullDist, MAX_DISTANCE);
  if (displayDist == 0 && skipZero<10) {
    // Try to filter zero readings
    skipZero++;
  return;
  }
  // Check if it is time to alter the leds
  if (now-lastDebouncePeriod > distDebounce) {
    lastDebouncePeriod = now;

    // Update parked status
    int parked = displayDist != 0 && displayDist<PARKED_DISTANCE;
    if (parked != oldParkedStatus && now-lastSend > sendInterval) {
      if (parked)
        Serial.println("Car Parked");
      else
        Serial.println("Car Gone");
#ifdef SEND_STATUS_TO_CONTROLLER
      send(msg.set(parked)); 
#endif
      oldParkedStatus = parked;
      lastSend = now;
    }

    if (parked && now-lastSend > PARK_OFF_TIMEOUT) {
      // We've been parked for a while now. Turn off all pixels
      for(int i=0;i<NUMPIXELS;i++){
        pixels.setPixelColor(i, pixels.Color(0,0,0)); 
      }
    } else {
      if (displayDist == 0) {
        // No reading from sensor, assume no object found
        numLightPixels--;
      } else {
        skipZero = 0;
        int newLightPixels = NUMPIXELS - (NUMPIXELS*(displayDist-PANIC_DISTANCE)/(MAX_DISTANCE-PANIC_DISTANCE));
        if (newLightPixels>numLightPixels) {
          // Fast raise
          numLightPixels += max((newLightPixels - numLightPixels) / 2, 1);
        } else if (newLightPixels<numLightPixels) {
          // Slow decent
          numLightPixels--;
        }
      }
  
      if (numLightPixels>=NUMPIXELS) {
        // Do some intense red blinking 
        if (now-lastBlinkPeriod > blinkInterval) {
          blinkColor = !blinkColor;
          lastBlinkPeriod = now;
        }
        for(int i=0;i<numLightPixels;i++){
          pixels.setPixelColor(i, pixels.Color(blinkColor?255*MAX_INTESITY/100:0,0,0)); 
        }              
      } else {
        for(int i=0;i<numLightPixels;i++){
          int r = 255 * i/NUMPIXELS;
          int g = 255 - r;     
          // pixels.Color takes RGB values, from 0,0,0 up to 255,255,255
          pixels.setPixelColor(i, pixels.Color(r*MAX_INTESITY/100,g*MAX_INTESITY/100,0)); 
        }
        // Turn off the rest
        for(int i=numLightPixels;i<NUMPIXELS;i++){
          pixels.setPixelColor(i, pixels.Color(0,0,0)); 
        }
      }
    }
    pixels.show(); // This sends the updated pixel color to the hardware.
  }

      }

This code is working. Variables was declared on 8b so max value at 255. Counter and timer can't take value above 255... Stupid.

How can i do to only send new value if new value is just more or less 0.2°C for example ?

[gohan]

Actually the code already checks if last temperature is different from current (see the first "else if" in the loop) but if you want you can change the condition to whatever you prefer in order to send only when difference is over a certain threshold or after a specific amount of time.

[ghislain]

I make this sketch, it is working, code may be cleaner but it's working...

Available on github : https://github.com/Gis70/MySensors/tree/master/ParkingTempHum_sensor